438495-24-0Relevant articles and documents
Ag-Catalyzed or Ag/PPh3-Catalyzed Chemoselective Switchable Cascade Reactions of N-Propargyl Thiocarbamoyl Fluorides and Malonate Esters
Cai, Zhongliang,Zhou, Junyi,Yu, Miao,Jiang, Liqin
supporting information, p. 293 - 298 (2022/01/12)
The divergent chemoselective synthesis of 2-methylene-2,3-dihydrothiazoles and 4-benzylidene pyrrolidine-2-thiones (most with E stereoselectivity) from N-propargyl thiocarbamoyl fluorides and malonate esters in moderate to excellent yields with a broad substrate scope and functional group tolerance has been accomplished. AgNTf2 catalyst at 60 °C in dichloroethane provided 4-benzylidene pyrrolidine-2-thiones. AgOTf catalyst and PPh3 ligand in refluxing acetonitrile resulted in a complete switch in the reactivity of formed α,α-diester thioamide intermediates followed by isomerization to access 2-methylene-2,3-dihydrothiazoles.
Solvent-free synthesis of propargylamines via A3 coupling reaction and organic pollutant degradation in aqueous condition using Cu/C catalyst
Rathod, Pramod V.,Puguan, John Marc C.,Kim, Hern
, (2020/09/04)
The present report focuses on the efficient and operationally simple synthesis of biomass-derived carbon as support to immobilize copper particles as a catalyst for the one-pot synthesis of propargylamines from furfural via the A3 coupling reaction. This new catalyst showed remarkable catalytic performance leading to a 97% yield within 5 h at 80 °C using 5 mg (0.0022 mmol Cu) of Cu/C catalyst under solvent-free condition. Moreover, nitro-substituted compounds such as 4-nitrophenol (4-NP) are highly toxic and not easily degradable. Hence, a quick and effective method is required to neutralize these toxic compounds. The synthesized active support Cu/C catalyst having various electron-donating groups containing small amounts of Cu plays an essential role in the catalytic reduction of 4-NP (0.1 g). Using only 3 mg (0.0013 mmol Cu) of Cu/C catalyst and NaBH4 (10 mmol), a 99% yield (100% selectivity) in the aqueous condition at 25 °C was achieved. The catalytic reduction follows the pseudo-first-order kinetics with reaction rate constant of 0.028 s?1. Moreover, results demonstrate that the Cu/C catalyst has superior catalytic activity due to the presence of electron-donating molecules such as O, S, and N atoms, which enable synergistic effect in enhancing the overall catalytic performance. Notably, the recoverability and recyclability of the synthesized catalyst were evaluated for up to four cycles, which confirmed its stability in these cycles.
Synthesis of Fully Substituted Pyrroles through a Copper-Catalyzed Aza-Michael/Claisen Rearrangement/Cyclization Cascade
Cui, Hai-Lei,Jiang, Lu,Jiang, Xue-Fei,Li, Meng-Fan,Liu, Si,Liu, Si-Wei,Tan, Hao,Tang, Xue,Yuan, Chang
supporting information, p. 723 - 729 (2020/04/07)
We have developed a copper-catalyzed aza-Michael/Claisen rearrangement/cyclization cascade sequence that affords structurally diverse pentasubstituted pyrroles in acceptable to good yields (31-84%).
